Page - 302 - in Maximilian Hell (1720–92) - And the Ends of Jesuit Science in Enlightenment Europe

Chapter 6302 telescopes used by himself and Father Sajnovics and the good accordance of the contacts observed during egress along with the remarks made on this occasion allow the observations to be treated as quite certain. […] Furthermore, one should note that Hell and Sajnovics were skilled ob- servers and that the Sun was higher above the horizon during both in- gress and egress than in any other site in Europe, with the exception of Orenburg [in Russia], where only the egress was observed.153 In his thesis, Powalky concluded that the solar parallax probably was around 8.86″,154 thus far larger than Encke’s conclusions and more in tune with Hell. In 1869, a prominent astronomer at the Académie des Sciences in Paris, Hervé Auguste Étienne Albans Faye (1814–1902), presented a paper in which he questioned some of Encke’s and von Littrow’s conclusions, particularly con- cerning the solar parallax (Faye advocated a solar parallax of 8.80 ±0.01″, which is indeed entirely correct).155 Carl Ludwig von Littrow, who in the meantime had been appointed director of the Vienna Observatory, reacted promptly by dispatching facsimiles of Hell’s manuscript to Paris. Of course, Professor Faye had no chance of detecting errors in von Littrow’s conclusions on the basis of the sets of black-and-white reproductions offered to him. In a follow-up article, he therefore agreed that the original journal must indeed have been edited before publication. Nevertheless, while admitting that Hell had arrived at some misguided conclusions in his theoretical works, he maintained that the editing in any case had been made with the best of intentions and underscored that Hell’s original manuscript proved his abilities as an observer. Looking ahead to the upcoming transit of Venus, Faye concluded that “the error of Fa- ther Hell’s observation, which he made without understanding its meaning, thus does not exceed 2.2 seconds in time. It will be difficult for us to do any better in 1874.”156 The solar parallax question was not resolved by the new sets of international observations of the Venus transit in 1874, and the Swiss as- tronomer Rudolf Wolf (1816–93) in his Geschichte der Astronomie (History of 153 Carl Rudolph Powalky, Neue Untersuchung des Venusdurchganges von 1769 zur Bestim- mung der Sonnenparallaxe (Kiel: C.F. Mohr, 1864), 15–16. 154 Cf. Hilmar W. Duerbeck, “Zach, Gotha, and the Venus Transits of the 18th and 19th Centu- ries,” in Balázs et al., European Scientist, 60. 155 Hervé Auguste Étienne Albans Faye, “Sur les passages de Vénus et la parallaxe du Soleil” [parts 1–2], Comptes rendus hebdomadaires des séances de l’Académie des Sciences 68 (1769): 42–50 and 69–73; Faye, “Examen critique des idées et des observations du P. Hell sur le passage de Venus de 1769,” Comptes rendus hebdomadaires des séances de l’Académie des Sciences 68 (1769): 282–90. See also Nielsen, “Pater Hell og Venuspassagen 1769.” 156 Faye, “Examen critique,” 287. See also Faye, “Sur les passages,” esp. 47–49 and 70.